Coastal beach ecosystems contaminated by marine litter impacting the coastal biodiversity, tourism, and sustainability.

This study examined the abundance, composition, sources, and pollution status of marine macro litter (>2.5 cm) at four beaches in Sri Lanka (Kallady, Negombo, Kandakuliya, and Balapitiya), located along the coastline of the northern Indian Ocean. Clean Coast Index (CCI), Plastic Abundance Index (PAI), Hazardous Item Index (HII), and Environmental Status Index (ESI) were used to evaluate the pollution levels. A total of 10,873 litter items were collected from four beaches representing 11 typologies. The average density of the litter collected was 0.7 to 1.2 items/m. Plastic items constituted the majority of litter found, with a percentage of 51%. Kallady Beach was classified as "extremely dirty," while the others were rated as "dirty" according to the CCI. All beaches fell under category "II" on the HII. PAI indicated high and moderate plastic contamination, and the ESI classified all sites as having a "bad" environmental status. The majority of litter originated from land-based sources, including unsustainable fishing practices, poor waste management, and harmful recreational activities. The findings highlight the urgent need for comprehensive marine and coastal management frameworks to address these challenges. Despite existing awareness and cleanup efforts, the study calls for innovative waste management solutions, enhanced regulations, corporate responsibility, and further research to protect Sri Lanka's coastal ecosystems. These effective management steps are essential to mitigate marine litter and ensure the long-term health of these sensitive ecosystems.